Hi Stitch,
>Got a question for all of you armament experts out there . . . . . was it possible to select which guns you could fire in most WWII fighters?
All variants of wiring up the guns were possible ... Pokryshkin even mentioned that it was impossible to fire all guns at the same time in one of the machines he flew.
The Luftwaffe had a selection by "A-Knopf" (trigger) or "B-Knopf" (pushbutton on top of the stick) by standard. Usually, they set up their aircraft to fire centreline guns with the A-Knopf and wing guns with the B-Knopf. For firing rockets and dropping bombs, there was the B2-Knopf (pushbutton on the side of the stick) on some machines. First steps towards HOTAS ...
The British fighters' weapons were operated electro-pneumatically and, if equipped with different calibre guns, had a pushbutton valve that allowed selective or simultaneous use, too.
The Navy initially had manually charged guns so that you could charge or lock individual guns by pulling and turning T handles on both sides of the seat. I'm not sure it was sensible to use these handles in air combat though, except maybe in an attempt to clear stoppages. Later Navy fighters might have had power-assisted systems too - I'm not sure of that right now. In any case, the idea was to have a way of making the guns safe for landing on a carrier deck, not to make them selectable in the air.
The USAAF had a variety of systems, usually electrically triggered. The P-51 did not have any way to arm or lock the 12.7 mm wing guns in flight (or to clear stoppages), while the P-39 seems to have had manually operated arming handles in early models and power-assisted system in later models. I've been told that some P-47 units used a switch to cut out one pair of machine guns in order to save ammunition for an emergency, or possibly for targets of opportunity, but this seems to have been an unauthorized modification at squadron level, and I've never seen it mentioned in the books.
Regards,
Henning (HoHun)